In 2015, the writer Ottessa Moshfegh published her debut novel, Eileen. Set in 1964, the book takes its title from the main character, a 24-year-old prison secretary who lives with her alcoholic ex-cop father. Eileen becomes obsessed with Rebecca, her older co-worker. The friendship results in death.

The novel is the first of Moshfegh’s books to be adapted for the screen—though Margot Robbie is currently developing her 2018 best-seller, My Year of Rest and Relaxation, into a feature. Moshfegh, who is also the author of the novels Death in Her Hands and Lapvona, collaborated with her husband, Luke Goebel, on the script. Directed by William Oldroyd, the movie stars Thomasin McKenzie as Eileen and Anne Hathaway as Rebecca. The film earned raves at the Sundance Film Festival this week, where it premiered. Ahead of a year on the film festival circuit, she answers our questionnaire about what she packs, eats, and buys while traveling.

Last flight you took?
It was a very easy one, San Francisco to Burbank. No luggage, no computer, even. And I was the first one on the plane and the last one off. A breeze.

What do you wear to the airport?
I try to dress a little more like an office professional and a little less like a weirdo writer. Maybe I’m imagining it, but I feel that if I wear, for example, a hoodie and sneakers, the flight attendant sees me as a teenaged derelict hoodlum who just shoplifted that Evian from the terminal and is using her drug-dealer boyfriend’s points to fly to Newark to go, like, do drugs or something. What I mean is, in my normal attire, I can look very young and angsty—at first glance—on a plane. To counteract this, I try to dress in some way that says, “I might be a corporate pod person.” You never know.

How long before your flight boards do you get to the airport?
I’ve been arriving about an hour before boarding, lately. In the past, I would get to the airport way too early and exhaust myself walking around with my backpack to kill the time.

Check bags, or carry-on only?
After years of overpacking and lugging around an entire wardrobe I won’t wear, I’m trying more and more to pack light and just bring my carry-on.

What do you bring in your carry-on?
If I’m traveling with a little suitcase, I put that up in the overhead compartment and just keep my purse with me at my seat. I usually have my MacBook Air with me, my glasses, some earplugs, and eye drops. And a toothbrush and mini-toothpaste. I’m a bit obsessive about brushing my teeth.

T.S.A. PreCheck, or regular?
T.S.A. PreCheck.

Favorite airport?
I like small airports. A few that come to mind: Bangor, Maine. Lanai, Hawaii. Palm Springs would make this list as well.

What do you buy in the airport terminal?
If I am traveling internationally, I might buy a bottle of perfume, which I will immediately unpack and misplace at home.

What do you do while waiting to board?
For many years, an airport terminal would trigger an immediate obsessive-compulsive response. I need a snack, I’d think, and I’d start wandering all the little shops. Let’s say I wanted a salad. I’d study the salads at the café. Then I’d go study the salads at the convenience stall. Then I’d go further, and there was another shop that sold salads. Which one was the best? I’d go around and around 10 times. If I’m paying $23 for lettuce, I want the best lettuce this airport has to offer, and so on. It was pretty crazy. Now I might get a latte and a muffin and do e-mails.

Item you can’t fly without?
Earplugs. I am very sensitive to noise. The ambient noise on a plane is enough to drive me insane.

First class, business, or coach?
I usually end up in business.

Window, middle, or aisle seat?
Aisle. I hate having to ask permission to go to the toilet.

How do you spend time in the air?
There’s something wonderful about watching a big Hollywood blockbuster on a three-inch screen. I will always watch something on a flight, if there’s time. I try to choose things that I haven’t heard of. I do like working too. My mind is a bit warped so high up in the air, and that can be good for writing sometimes.

Do you buy Wi-Fi?
Very rarely. On long flights with bad movies.

Do you eat plane food?
Yes, I adore plane food. It’s so fun. Since childhood, I’ve loved these weird meals in the sky. They remind me of being an astronaut.

Best plane food you’ve ever had?
The best plane food I ever had was on a first-class flight from Tokyo back to LAX. Everything was exquisite and fresh. I remember that flight more than my time in Tokyo, in fact. (I need to go back!)

Best drink to get on a flight?
I hear that ordering Diet Coke on a plane is very hard on the flight attendants. It fizzes so much, it takes them too long to pour it. But I still do it, when I need some caffeine. Otherwise, it’s water for me.

Do you talk to the people sitting next to you?
The most I will do is politely negotiate the shared space under the seat in front of us, and the armrest. I like having very clear boundaries like that. And then, silence.

Keep shoes on or off on the plane?

What do you do when turbulence hits?
I get a kick out of turbulence. I just hold on to my Diet Coke and keep on doing what I’m doing.

Worst part of the flight?
The worst part is toward the end of the flight. The toilet has been completely destroyed. It is now a closet full of piss and dirtied paper towels. Not the best location to brush one’s teeth.

First thing you do when the plane lands?
Use my iPhone, of course, like the rest of the pod people.

Advice for travelers?
Be more polite than you think you should be. It will earn you double points in heaven.

The Sundance Film Festival’s final screening of Eileen, adapted from Ottessa Moshfegh’s novel of the same name, is tonight. The film will hit theaters later this year